package org.as3search.criteria {
	/*
	 * as3search - http://code.google.com/p/as3search
	 * Copyright (c) 2009-2010 by respective authors. All rights reserved.
	 *
	 * This library is free software; you can redistribute it and/or modify it under the
	 * terms of the GNU Lesser General Public License as published by the Free Software
	 * Foundation; either version 2.1 of the License, or (at your option) any later
	 * version.
	 *
	 * This library is distributed in the hope that it will be useful, but WITHOUT ANY
	 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
	 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
	 *
	 * You should have received a copy of the GNU Lesser General Public License along
	 * with this library; if not, write to the Free Software Foundation, Inc.,
	 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	 */
	
	/**
	 * <code>NotExpression</code> evaluates that another
	 * <code>Criterion</code> instance evaluates to false. In 
	 * laymans' terms, it returns the opposite of what the 
	 * <code>Criterion</code> instance would return.
	 */
	public class NotExpression implements Criterion {
		
		private var _criterion:Criterion;
		/**
		 * Creates a new <code>NotExpression</code> instance.
		 * @param	value	The <code>Criterion</code> instance which will be used to
		 * 		evaluate this expression.
		 */
		public function NotExpression(value:Criterion) {
			criterion = value;
		}
		/**
		 * @inheritDoc
		 */
		public function evaluate(value:Object):Boolean {
			return !criterion.evaluate(value);
		}
		/**
		 * The <code>Criterion</code> instance that this <code>NotExpression
		 * </code> evaluates values with.
		 */
		public function get criterion():Criterion { return _criterion; }
		public function set criterion(value:Criterion):void {
			if (value == null)
				throw new ArgumentError("'criterion' cannot be null!");
			
			_criterion = value;
		}
	}
}